The invention generally relates to display apparatus and, particularly, to a backlit motion display apparatus for displaying a series of advertisements or other images in a predetermined manner.
In general, backlit displays, especially those which scroll from one image to another, provide effective advertising in a reliable, user-friendly, multi-image format. A conventional scrolling display apparatus uses a backlit light box, free standing on a pedestal or mounted on a wall, that displays several different images in a single sign. The images are typically printed in frames on a flexible polyester film that is wound on a scrolling spool system. Often, the spool system advances the film scroll for displaying each frame for a predetermined amount of time. Such a display usually advances the frames consecutively in one scroll direction and then in the other or in a single direction and then rewinds the film.
Presently available motion displays use marks to indicate, for example, the centers of the frames. However, centering and other kinds of marks are first printed on tape and then adhered to the surface of the film. This is because typical mark reading devices reflect light off of the tape to detect the marks and conventional film materials are not well suited for reflecting light in this manner. In addition to adding a labor-intensive production step, the tape tends to slip over time and, thus, introduces positioning errors. Moreover, a sticky residue is left on the surface of the film as a result of the slippage. This residue attracts dirt and interferes with mark detection.
Further, motion displays presently use an open loop control scheme for advancing and positioning the frames. Such open loop systems rely on, for example, a time-base only and do not determine the position of the scroll. These open loop motion displays typically run at full speed for a portion of a velocity profile and then shift to a much slower speed while hunting for a centering mark. Due to variations in film length and mass, friction and motor torque, these motion displays must spend almost half of the velocity profile in a slow speed in order to avoid overshooting the centering mark. As a result, presently available motion displays using open loop control schemes fail to provide a desired level of efficiency.
For these reasons, a backlit motion display is desired providing accurate, reliable, closed loop control and which permits printing centering marks, end marks and/or bar codes directly on the film.
Often, an advertiser wishes to provide prospective customers with not only visual displays but also accompanying jingles, additional information, discounts, store directions or the like in connection with the advertisement to enhance its effectiveness. Unfortunately, presently available motion displays are not well suited for these types of enhancements. For this reason, a backlit display providing a convenient and flexible interface to other devices, such as coupon printers, sound controllers and other peripherals is desired.
The invention meets the above needs and overcomes the deficiencies of the prior art by providing an improved backlit display apparatus. Among the several objects and features of the present invention may be noted the provision of such display apparatus that permits convenient interfacing with peripherals; the provision of such display apparatus that permits accurate and reliable mark detection; the provision of such display apparatus that permits accurate and reliable closed loop position, speed and frame sequence control; and the provision of such display apparatus that is economically feasible and commercially practical.
A backlit display apparatus embodying aspects of the invention includes a film supported on a motor-driven spool. The spool has at least a portion of the film wound on it and is positioned so that at least another portion of the film is in front of a light source and within a desired viewing area. The film has a series of frames and at least one mark printed on it corresponding to each frame. The marks provide information representative of frame position relative to the film. The light source, positioned behind the film relative to an intended viewer in front of the film, illuminates the frames. When illuminated, each frame displays an image printed on the film. The apparatus also includes a detector for detecting the marks printed on the film as the film is advanced by the motor. An encoder associated with the motor detects the position of the frames as a function of the angular position of the motor when each mark on the film is detected. In response, the encoder generates a position signal representative of the detected positions of the frames. The apparatus further includes a processor receiving and responsive to the position signal from the encoder for controlling the motor to advance the film so that a selected frame is within the desired viewing area for a predetermined interval of time.
In another embodiment, a backlit display apparatus includes a film having a frame and at least one mark printed on it corresponding to the frame. The mark provides information identifying an image printed on the film. A light source, positioned behind the film relative to an intended viewer in front of the film, illuminates the frame. When illuminated within a desired viewing area, the frame displays an image printed on the film. The apparatus also includes a detector for detecting the mark printed on the film and a processor responsive to the detector for identifying the image being displayed and generating a signal representative of the identification. In turn, a peripheral, receiving and responsive to the identification signal from the processor, provides multimedia enhancements to the displayed image.
Alternatively, the invention may comprise various other methods and systems.
Other objects and features will be in part apparent and in part pointed out hereinafter.